It seems that the date/time information transmitted by the cellular network (and used to synchronize the time between the Network and BB) includes the following components:

1) GMT time and date
2) local DST adjusted time and date

Can someone confirm that GMT is really included and if so, is it always transmitted by all carriers (US/Canadian/Asian CDMA and European/Asian GSM carriers).

I was playing around with the world clock "TrackIt TimeZone Edition" from Javatek Media and there was no way to fool it that I was in a different time zone than the real one. No matter what Time Zone I set in BB in Options - Date/Time (Hawaii, Dubai, whatever), the world clock somehow knew that I was really in US EST and it was always calculating the same, correct time and date for all selected cities.

The only explanation seems that the cell tower is transmitting time in GMT or that it is transmitting the time zone code.

I have sorted this out. It has nothing to do with GMT but with a peculiar way TrackIt TimeZone Edition works. It is synchronizing its world clocks with BB Local Time (Options - Date/Time - Time) and not with BB Time Zone. I changed the Local Time manually just to confirms this:

When you travel to a different time zone, let's say to Hawaii, as long as you leave Date/Time Source in your BB set to Network, you need to start TrackIt and change its internal "Local Time Zone" to US/Hawaii.

I wish they mentioned all this in their application's Help on BB. I have finally found the relevant web page right now, here is the link:

When you travel to a different time zone, let's say to Hawaii, as long as you leave Date/Time Source in your BB set to Network, you need to start TrackIt and change its internal "Local Time Zone" to US/Hawaii.

Actually I'm not sure about this part. After more testing new questions have emerged so I submitted the ticket to support at TrackIt TimeZone's website.